“Slightly different” ticket machines. Why?

Here’s Kelly Sinoski’s report in the Sun on people’s troubles using their credit cards to buy tickets for the Canada Line. I can’t get too worked up about it. We knew there were going to be glitches when the Canada Line opened. This is one. One way or another, it’ll get worked out. Once the bus routes all change in September and more people start taking the Canada Line every day, there’s going to be more little glitches. They’ll get worked out too.

But something else about the Canada Line ticket machines seems like a dumb move:

The regional transportation authority maintains the high-tech ticket-vending machines are working properly, but are slightly different from those in the Expo and Millennium SkyTrain stations.

Why have different machines for different Skytrain line? Seriously. Was there something wrong with the old machines on the old Skytrain Lines? I guess they’re not set up to charge any “surcharges” like the extra airport fee, but couldn’t that function be added to machines that were otherwise exactly like the old machines?

Lack of continuity of little details–like how ticket machines work–makes the whole system harder to use. It means, for example, that transit riders need to figure out how to buy a ticket twice–once for the old Skytrain Lines and once for the Canada Line. Why make people go through that extra step?